Sensors 2015, 15, 10452-10464; doi:10.3390/s150510452 OPEN ACCESS
sensors ISSN 1424-8220 www.mdpi.com/journal/sensors Article
Dynamic Response of Tapered Optical Multimode Fiber Coated with Carbon Nanotubes for Ethanol Sensing Application Arafat Shabaneh 1,2, Saad Girei 1,2, Punitha Arasu 1,2, Mohd Mahdi 1,2, Suraya Rashid 3, Suriati Paiman 4 and Mohd Yaacob 1,2,* 1
2
3
4
Wireless and Photonics Network Research Centre, Engineering and Technology Complex, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia; E-Mails:
[email protected] (A.S.);
[email protected] (S.G.);
[email protected] (P.A.);
[email protected] (M.M.) Photonics Laboratory, Department of Computer & Communications Systems Engineering, Faculty of Engineering, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia Department of Chemical and Environmental Engineering, Faculty of Engineering, Universiti Putra Malaysia, 43300 Serdang, Selangor, Malaysia; E-Mail:
[email protected] Department of Physics, Faculty of Science, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia; E-Mail:
[email protected]
* Author to whom correspondence should be addressed; E-Mail:
[email protected]; Tel.: +603-8946-4345. Academic Editor: Tindaro Ioppolo Received: 19 November 2014 / Accepted: 26 January 2015 / Published: 4 May 2015
Abstract: Ethanol is a highly combustible chemical universally designed for biomedical applications. In this paper, optical sensing performance of tapered multimode fiber tip coated with carbon nanotube (CNT) thin film towards aqueous ethanol with different concentrations is investigated. The tapered optical multimode fiber tip is coated with CNT using drop-casting technique and is annealed at 70 °C to enhance the binding of the nanomaterial to the silica fiber tip. The optical fiber tip and the CNT sensing layer are micro-characterized using FESEM and Raman spectroscopy techniques. When the developed sensor was exposed to different concentrations of ethanol (5% to 80%), the sensor reflectance reduced proportionally. The developed sensors showed high sensitivity, repeatability and fast responses (
